Intake and diet preference of dairy heifers grazing mixed or alternating rows of birdsfoot trefoil and cool-season grasses

cattle;diet selection;dry-matter intake;legume;orchardgrass;perennial ryegrass;tall fescue;utilization Background:Mixtures with birdsfoot trefoil(BFT)increase herbage intake in grazing cattle.We hypothesized that BFT spatially separated from grasses would increase preferential grazing of BFT and herbage intake compared to grass and BFT in mixed rows.Methods:Binary mixtures of BFT were established with orchardgrass,meadow bromegrass,tall fescue,and perennial ryegrass in alternating and in mixed rows.Pastures were rotationally stocked with Jersey heifers,and herbage mass,intake,and preferential grazing were estimated.Results:Planting BFT in alternating rows did not affect herbage mass,intake,or BFT preference.Regardless of spatial arrangement,pasture production averaged 4116 kg ha−1 per rotation,of which 32%was BFT.BFT comprised 39%of herbage intake in alternating and mixed rows,7%greater(p=0.001)than offered,indicating partial preference for BFT.Greatest preferential grazing of BFT was in tall fescue and orchardgrass mixtures,but less than commonly reported for legumes grown in more contrasting spatial arrangements with cool-season grasses.Conclusions:Grazing heifers showed partial preference for BFT over grass.However,the lack of an effect of spatial arrangement on herbage mass,herbage intake,and diet preference indicates that spatial arrangements greater than alternating rows may be needed to increase overall herbage intake.

Influence of harvest date on seed yield and quality in forage kochia

Forage kochia(Bassia prostrata) is used for rangeland reclamation and livestock and wildlife forage,but limited research has been conducted on its seed production. Therefore, this research evaluated the effect of harvest date on seed weight, germination, and seed yield of forage kochia subspecies virescens and grisea. Seed was harvested from individual plants for 3 years during October, November, and December. October harvest had the lightest 100-seed weights, with the November harvest slightly heavier than December, for most accessions.Cultivar Snowstorm and breeding line Sahsel, both subsp. grisea, had the greatest 100-seed weights in November, 155 and 143 mg, respectively, whereas, cv.Immigrant(subsp. virescens), the standard for forage kochia, ranked among the least for 100-seed weight. For most accessions, germination was lowest from the October harvest(11%–43%), with greater germination with November and December harvested seeds(43%–64%).Viable seed yields were greatest in November with the exception of two accessions, which peaked in October,indicating earlier maturity. Results indicate that forage kochia usually reaches optimum seed maturity by early November, after plants are exposed to freezing temperatures; however, earlier maturing accessions exist in both subspecies virescens and grisea.